Facile synthesis of ultra-large, single-crystal Ag nanosheet-assembled films at chloroform-water interface

Highlights: • The Ag nanosheets and their assembled films were prepared at CHCl₃–H₂O interface. • The Ag nanosheets possess very thin, ultra-large and single crystal structures. • The formation of films originated from interfacial diffusion-limited aggregation. • The Ag films exhibit remarkable SERS response and high reproducibility. -- Abstract: The ultra-large, single-crystal Ag nanosheets and their assembled films can be easily one-pot prepared at room temperature via a chloroform-water interfacial reaction route with o-ethoxyaniline (OEA) in chloroform as reductant and AgNO₃ in water as precursor. The as-obtained single-crystal Ag nanosheets can reach as large as 16 μm in side length and as thin as 22 nm in thickness. The results show that reagent concentrations, temperature and organic phase in current liquid-liquid reaction have significant influences on the formation of Ag sheet-like nanostructures. The possible mechanism was proposed for the growth and formation of Ag nanosheets and their assembled films. Furthermore, using p-aminothiophenol (PATP) as a model molecular probe, the Ag nanosheet-assembled films exhibit outstanding surface-enhanced Raman scattering (SERS) response and high reproducibility.